


Sentinel

by singingwithoutwords



Category: Marvel Cinematic Universe, The Avengers (Marvel) - All Media Types
Genre: (humans can packbond with literally anyone or anything), Alternate Universe, Domestic Avengers, Feels, Fluff and Angst, Team as Family, also the kickass ladies stick around this time, basically the mcu with extra characters and tony stark is an ancient alien, idk how to explain this plot or tag for any of it, tags will probably be updated as I go along, this alien is our now and we love him
Language: English
Status: In-Progress
Published: 2018-05-13
Updated: 2018-08-08
Packaged: 2019-05-06 05:58:49
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 3
Words: 3,217
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/14635527
Author URL: https://archiveofourown.org/users/singingwithoutwords/pseuds/singingwithoutwords
Summary: Sometimes the things one guards aren't to be touched.  Sometimes they are.





	1. Prologue

**Author's Note:**

> This was mainly inspired by the Cruxshadows song [Titan](https://www.youtube.com/watch?v=hUelPm-kc2Y), but bears only a passing resemblance to the lyrics. What can ya do.  
> /shrug emoji
> 
> Anyway, hopefully y'all enjoy this one because it will not leave me be.

_ He sings as he waits, still within the void, surrounded by silence and the coffins of his brethren.  In the endless stretches of peace, when nothing living or made moves within the considerable range of the sensors, he sings a litany of names, repeating them again and again, the only honor they will ever be given.  They are worn, those names, softened by countless repetitions, smooth on his tongue and familiar to his ears. He sits in his lonely cockpit, unmoving as the vessels he controls, singing their names, until something stirs. _

_ He sings as he fights, intoning hymns of war so ancient that few remember the civilizations that created them.  He sings as he kills, destroying any that seek what he guards. He cries as he sings, with eyes that have seen too much, for a heart that has lost so much yet cannot simply cease to feel. _

_ Then the battle ends, and stillness reigns, and he begins the litany again. _

_ His voice echoes back to him a dozen, a hundred times: even though he has long since shut down all visuals, he cannot bear to completely sever communications.  They are all gone, but he will not leave them in silence. Far from their homes and their gods - if indeed their gods ever existed - they will have the scant comfort of his voice, until he, too, falls. _

_ He is the last.  He will fall. He knows this.  He accepts this. He will fall, and Midgard will fall with him.  He is doomed to fail. All he can do is stave off failure as long as possible. _

_ So he waits. _

_ And he sings. _

 

* * *

 

There is a painting, attributed to at least five different artists.  It depicts an armored giant, surrounded by a nimbus of stars, standing guard over a walled city.  It is unsigned; the back of it bears a single sentence, hastily scratched in pen. No one can agree if the sentence was written by the same hand that painted the piece.  Everyone, however, readily agrees on what it means.  _ Eternamente restano vigili _ , it reads.   _ Eternally they remain vigilant _ .

There is a drawing in a cave, ancient as humans reckon things.  It depicts a crude figure holding a weapon of some sort. Ranged behind it are many much smaller figures and animals, huddled close to it as if for protection.

There is a carved figurine found in Argentina, of a humanoid shape in fantastic armor and what once had been a crown of stars, armed with a flaming sword.

There is a mural in Pompeii, preserved beneath the ash, of a glowing man against a field of stars, titled  _ laniatum excubiarum _ .    _ Sentinel _ .

There is a painted vase in Athens, depicting a great battle among the stars.

There is a tale, a dozen different versions told by a dozen First Nations, of great sky warriors who protect the Earth from harm.

There is a footnote in a translation of the  _ Prose Edda _ , marking an unclear passage that might refer to some hitherto unknown guard.

There is a poem.  There is a story. There is a painting, a statue, a relief, a song, a scattering of clues strewn carelessly across the globe, through so many cultures and civilizations that they can’t possibly be connected.  Surely they must refer to something else, something different, something familiar. Surely.

Surely whatever they refer to can’t be  _ real _ .


	2. Mystery of the Whisper

Steve Rogers liked to think he’d seen a lot in his life (which was short or long depending on who you asked, which told you all you needed to know about his relationship with ambiguity).  He’d become a supersoldier, fought in a war, lost his best friend, crashed into the ocean, missed a dance, and woken to a future unlike anything he could have dreamed of back in the 30s and 40s.

Sure, there were no cities on Mars yet, and flying cars still weren’t available to the general public, but the internet was a marvel, the music was amazing, the special effects in pictures were almost impossible to tell from practical ones, and don’t even get him started on the food.

He had mixed feelings about the superhero situation.  On the one hand, it was nice to not be the only enhanced person around; on the other hand, he could do without the supervillains that were the reason most of the heroes were around in the first place.  He liked his team, but he’d rather there not be such a need for them. He preferred his excitement a little less hostile, thank you.

He also had mixed feelings about the signal.  That’s what they were all calling it,  _ the signal _ .  All anyone had to do was stress the words in the right way, and everyone would know what they were talking about.

Natasha had been the first to hear it and realize it  _ was _ a signal.  She was prone to insomnia, and liked to spend her sleepless nights doing productive things, like spelling whoever had comm duty, or cleaning and inventorying every weapon in SHIELD’s impressive training rooms.  She’d been up keeping Jan company at the comms when she’d heard the first whisper that might have been a word. She’d marked it and gone to bed, returning after a few hours’ sleep to listen to it again. She’d tracked it back, finding bits and piece of it in older recordings.

Inevitably, Hank and Jan had offered to help her, slowly drawing the rest of the Avengers into it, until it was an official part of comm watch duties: listen for the signal, isolate it if you find it, add it to the log.

It took months of listening and piecing it together before they felt  sure they had all of it.  It went on for two hours, nineteen minutes, and forty-seven seconds, in a language that none of them were familiar with, and it carried with it one short, very clear message.

Something was out there.

Natasha called for caution.  It might be hostile. It could be an invasion on the way.  Steve agreed with her.

Jan argued that it might be friendly, and just want to say hello, and they should reach out to it.  Steve agreed with her, too.

It was a topic of hot debate during their downtime, which was slightly less destructive than Mario Kart, so more power to them.  Steve kept mostly out of it, content to let everyone else argue. As long as whatever was out there stayed out there, he had no complaints.  If it started moving toward Earth, then he’d make up his mind about it. For now, he was fine with ambiguity.

 

* * *

 

Clint, fresh off one hell of a mission so classified he couldn’t even tell his teammates about it, walked into the common room to find half of said teammates huddled together and arguing in low voices that meant someone with superhearing was asleep.  He debated the merits of a shower and his own bed, decided that was too much effort, and flopped down on the floor at their feet (Coulson would murder him if he put any part of his filthy self on the furniture).

“Who are we trying not to wake up, and what are we arguing about?” he asked.

“Steve fell asleep 41 minutes ago, and the signal,” Jan answered.  “Specifically, whether it’s being broadcast accidentally or deliberately.”

“Ah- the nerd side of the issue,” Clint said, nodding to himself and lacing his hands together over his stomach.  “Don’t mind me, then- I have nothing to contribute.”

“Us ‘nerds’ are arguing the more important side of the issue,” Hank informed him, with way more gravity than talking to someone lying on the floor warranted.  “You should be thanking us.”

Clint snorted.  He didn’t really care one way or the other about the signal, but he did enjoy getting Hank worked up.  “Thank you, nerds.”

Jan giggled.  Hank rolled his eyes in exasperation.  Betty rolled hers in amusement.

“Why don’t you go clean up and get some sleep?” Jan suggested.  “We’ll keep debating, and I’ll let you know what we come up with while you’re on comm duty tonight?”

Clint groaned.  “You can’t put the tired deaf guy on comm duty, it’s not nice.  Make Bruce do it.”

“Bruce did it last night,” Betty said.  “And I did it the night before last. Ask someone else.”

Clint tilted his head back far enough to look beseechingly at Jan and Hank.

“We have a date,” they said simultaneously.  Jan said it apologetically; Hank said it smugly.

“I hate you all,” Clint announced, hauling himself back to his feet.  “I’m going to bed.”

“Shower first,” Jan admonished.  Clint grumbled noncommittally as he trudged back toward the bunks.

He did shower first, though.  Jan would know if he didn’t.

 

* * *

 

Jane Foster was not an Avenger.  She would just as soon leave the superheroing to other, more reckless people.  People with actual superpowers. She wasn’t even technically a member of SHIELD- she was an outside contractor, a consultant on retainer with the Avengers specifically; between them, Bruce, Betty, Hank, and Jan knew quite a bit of science, but none of them was an astrophysicist.

Technicalities and actualities aside, though, Jane might just as well be an Avenger.  She lived on their base, did most of her work in their labs, and had regular contact with three people who weren’t Avengers (or, in Betty’s case, honorary Avengers).

The Avengers had, of course, brought her in as soon as they realized they were picking up an extraterrestrial signal.  Since she wasn’t an Avenger, Jane had the most free time to devote to studying the signal, while everyone else had missions or training taking up their time, and she felt she knew it best.

She understood where Natasha was coming from, and she didn’t blame her for being firmly on team What If It’s Hostile, but Jane was very much the captain of team It’s Definitely Friendly (Or Neutral At Worst).

Jane listened to the signal so often she had portions of it memorized.  And while it could just be the strange alien language it was in, every repeat convinced her more and more that it was a song.  A sad song. A heartbreaking song, a song of grief and loss. Darcy claimed she was projecting, but Jane would bet all the money SHIELD had ever paid her that they were eavesdropping on an alien in mourning, and it made her want to hug it, assuming it could be hugged.

Jane had told only Darcy and Betty about her opinion, and sworn them both to secrecy, but she always tossed in her support whenever Jan voiced her desire to reach out to whatever was out there.

Meanwhile, she pulled extra comm duty, searched for some way to find their mysterious crooner, and listened.

 

* * *

 

“We know where it’s coming from,” Jane announced as she strode into the common room in the middle of movie night, her eyes bright with excitement.

Jan frowned, twisting around in her seat.  “I thought it was moving too much to nail down,” she protested.

“No, it’s not moving at all,” Jane disagreed, holding out the stack of papers she’d been clutching to her chest.  “It’s  _ echoing _ .  It’s just at such an extreme we were only catching occasional bounces until we started actively looking, and even now it’s too far to be consistent.”

Jan nodded, looking over each paper and then shoving it in Hank’s direction for him to look at, too, while Bruce abandoned the movie and hurried over.  “And if we know where the echos are-”

“-we can pinpoint the origin,” Bruce finished, reading over Hank’s shoulder.  “And we can send something back.”

Jane nodded eagerly, all but bouncing in place.  “Exactly. I’ve already talked to Director Fury, he says if we all agree, we can put together a welcome package.”

They turned almost as one to stare at Natasha, comfortably wedged into the big armchair next to Clint.  She stared impassively back at them.

“We still don’t know if it’s hostile.”

“We also still don’t know if it’s not,” Jan retorted, sighing.  “Come on, don’t you want to be there for mankind’s first real contact with aliens?”

“It’s only a matter of time before someone else picks up on this, assuming they haven’t already,” Hank pointed out.  “Do you really want someone like Doom being the first contact whoever this is has with Earth?”

Natasha frowned, mulling that over.  It was a good point.

“Personally,” Bucky spoke up, “I’d rather take a chance on contacting it ourselves than run the risk of Hydra doing it for us.  They don’t exactly need cooperation.”

A collective wince ran through the room.  Couldn’t really argue against that, given Bucky’s own history with Hydra.

“Since you seem to have all the counterarguments, I don’t have much of a choice, do I?” Natasha asked, shrugging.  “You win. Let’s contact us an alien.”

Jan squealed happily, bouncing out of her seat and hurrying over to throw her arms around Natasha.  “I promise if it’s a bad alien, you can stab it first.”

Natasha smiled, hugging back.  “And I promise not to say ‘I told you so’ while I stab it.”

 

* * *

 

Once they reached a decision and formed a plan, it was quickly put into action.  In less than a day, they had a preliminary response written up. In less than a week, they’d finalized it.  Two days more, they’d recorded it in every language they knew between them, which was frankly a staggering number.  Jane handled the actual programming and volunteered to monitor it in real time. They took a day for second thoughts, then, after exactly two weeks almost to the hour, released a signal of their own.

 

* * *

 

He noticed it immediately, alert to the slightest change in the cascade of noise and data surrounding him, watching for the least sign of failure: it was a soft beep, a quiet pinging at the edges of his awareness, and it should not be there.

It was a signal, coming not from beyond his position, but from behind him.  Inside the ring. From Midgard. Not an aimless drifting fragment, as he’d caught before, but a full signal, complete and targeted.  Deliberately sent.

He hesitated, uncertain for the first time in years beyond counting.  Caution and curiosity warred within him, but only for a moment; he would not be here, after all, if he were ever overly concerned with caution.

He opened himself to the signal.

For the first time in eons, he heard a voice which was not his own.


	3. Ethernaut

He didn’t know exactly how long he’d been here, how much time had passed since he’d accepted this post.  He’d counted in the beginning, long ago, when they had numbered a thousand and the monotony of the days had been soothed by the fellowship they shared.

Now, when time was a single indistinguishable blur, with nothing to look forward to but another battle which might prove to be his last, he saw no point in counting.  Time did not touch him anymore, so he paid it no notice.

The Midgard he’d been charged to protect had been a primitive world, lacking in so many ways, but the time that had passed him by had not done likewise with Midgard.

The technology that had been used to reach out to him was still primitive by the standards of his people, but represented Ages of progress for the senders.  Audio in a dozen or more languages accompanied records of mathematics and sciences, visual archives of Midgardian adults that seemed like bright, innocent children to his ancient eyes.

Something in them, some aspect of their enthusiasm and openness, reached a part of him he’d thought - prayed - had died long ago.  A part that yearned for companionship, that craved voices not his own and more than memories for friends. A part that remembered a time countless centuries, millennia, ago when his planet had been alive, his people had thrived, and he had always been surrounded by warmth and love.

He’d thought that part of him had withered away from disuse, that he had ignored it long enough for it to fade away, dead and gone like every being of any species he had ever known.

Time, it seemed, had chosen not to touch him even in ways that would have been to his benefit.

He gave more of his attention than he likely should to the recordings, unable to help himself.  Less than half the fleet remained, half-repaired patched-together hulls that carried within them the remains of their original pilots.  Time had not been kind to them, and many were a single battle more from destruction. Controlling them all himself was taxing, but the loss of any of them was a blow to Midgard’s defenses, made his own final battle that much more inevitable.  And now his attention strayed, robbing the defense ring further, for the sake of the innocent words of children.

Was it wrong of him, to draw comfort from them?  To be moved by them? To want more? His duty was never meant to be solitary, and his kind needed companionship more, perhaps, than most.  He would not abandon his post, but he felt he could be pardoned for the comfort even this once-removed contact gave him, and for his desire for more.

He fought himself as he listened, as he watched.  Fought the overwhelming urge to respond in kind, to reach out, to let them know their messages had reached him.  To let them know he was there. He should not,  _ could _ not, yet the urge remained, and his logic and loneliness did battle within him.

He came to the end of the data, to the final file.  It was audio, an imperfect recording of his own voice fading and strengthening through static, singing the litany of names.  But unlike every repeat since the last of his companions fell, he did not sing it alone.

Alongside his voice, striving to match it, obviously repeating from rote memorization rather than knowledge of what the words meant, was a soft voice he recognized as belonging to one of the Midgardians, with long brown hair and dark bright eyes that shone with love for the knowledge she shared.  The audio was not accompanied by visuals, but he could see her nonetheless, hear the heartbreak and sympathy in her uncertain voice, the tears he refused to shed that she seemed more than willing to shed for him.

For so long, the only voice he heard had been his own.  For so long, his pain and grief had gone unheard by any but the stars.  For so long, he had been completely and utterly alone.

Anything else, he could have withstood.  Faced with understanding that needed no common language, that dismissed distance and time and species, with a soul that knew his grief and understood it and  _ shared _ it, he was defenseless.

He did not hesitate, as the recording faded into silence as absolute as that of the Void.  He reached out, activating parts of the communication relay that had lain dormant for so very long, and - for the first time in what felt like several lifetimes - spoke to a being not himself.

“Midgard, this is Sentinel Eight Seven One: do you read me?”

**Author's Note:**

> Apologies for any and all translation fails. I am a smol monolingual bean, and I blame Google.


End file.
